The glass transition involves a minor change in the internal energy, and yet the physical and mechanical properties of a glass change dramatically. In order to determine the evolution of the atomic structure through the glass transition, in-situ synchrotron X-ray scattering measurements as a function of temperature on metallic glass were conducted. It is found that the thermal expansion at the atomic level is smaller than the macroscopic thermal expansion, and significantly increases above the glass transition temperature (Tg). It is also found that the relative change of the quantity(N represents the number of atom pairs), with significantly longer interatomic distances for the nearest atomic pairs, increases above Tg. These phenomena consist with the interconnecting zone connected tight-banded-cluster amorphous model. This model contains essentially three major parts: (I) clusters with tight bonding; (II) loosely bonded free volume regions between clusters; and (III) interconnecting zones, which interconnect the clusters.